DE1961804A1 - Cylinder head mounting for reciprocating internal combustion engines - Google Patents

Description

KHD

KLÖCKNER-HUMBOLDT-DEUTZ AQ · COLOGNE

5 Cologne-Deutz, Nov 10th 1969 D 69/65 - TP So / B

Cylinder head mounting for
Reciprocating internal combustion engines

The invention relates to a cylinder head mount for a Reciprocating internal combustion engine in Heihen and V design with individual cylinder heads, in the case of two adjacent cylinder heads with the cylinder and the crankcase by means of tie rods are tense.

With cylinder heads of reciprocating internal combustion engines with increasing thermal and mechanical stress, strength and deformation problems, which lead to a further increase in the Set a limit in terms of material load and thus an increase in performance of the machine · With light metal cylinder heads In air-cooled internal combustion engines, the material strength limit is due to the fact that the construction is broken up for the purpose of cooling nooh further reduced. The arrangement of the fastening screws in the cylinder head is particularly difficult because the screw forces that the cylinder head with the cylinder and brace the crankcase, cause severe deformation.

It is known that the fastening screws for the cylinder head; depending on the number, all or part of the locally expanded To arrange the separating line between two cylinder units and to pull both cylinder heads over a washer or bracket with the

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To tighten the cylinder crankcase. The disadvantage here is that differences in height due to the mounting tolerances between the two cylinder units are not balanced, resulting in high edge pressures and additional stress of the screw by bending.

It is also known to transmit the screw forces via a spherical washer with a corresponding counter bearing. This has the disadvantage that the screw force acts on the edge or near the edge of the cylinder head, which süi, caused by the shape of the joining surface between cylinder head and cylinder, results in a tilting moment that the cylinder head at one-sided loosening the fastening screws tilts. This has the advantage of facilitating the assembly and disassembly of individual cylinder units canceled because all screws have to be loosened.

Finally, an air-cooled internal combustion engine is known (German patent specification 940 075 and Motorteehn. Zeitschrift 1968, issue 4 »pp. 132-138), in which the cylinder head attachment by means of expansion screws, which are partly in the gas ducts

len are arranged. This has the disadvantage that the screw arrangement and the channel shape must be matched to one another, although the inlet channel shape mainly depends on the requirement is determined to give the air flowing into the cylinder a swirl. On the other hand, the screw pad is about arranged at the level of the cylinder head base, the height of which for Absorption of the bending moment, caused by the very

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forces, -with increasing thermal load on the machine not enough. Deformations occur, especially in the area of the exhaust duct, which depends on the temperature level reached lead to permanent deformation. A decrease in the screw force and leaks between the cylinder head and the cylinder are the consequence.

It is the object of the invention, the screw fastening of the Zy ^ to shape linderkpfes so that this has little effect on the Position and shape of the gas exchange channels and the screw force as directly as possible in the Pi | e or pressure surface between Cylinder head and cylinder is directed.

According to the invention, this object is achieved in that in each case two adjacent cylinder heads are braced together with the crankcase by means of one or more expansion screws via a bridge. As a result, the routing of the gas exchange channels is largely independent of the screw position. Due to the high force application point of the bridge, the pressure distribution in the cylinder head is more favorable and the contact pressure of the joining surfaces is more even. In addition, the support points of the bridge are arranged almost vertically above the center of gravity of the Yieruel ^ joining surface between the cylinder head and the cylinder, which means that this is initiated by the screw force = Bie ^ anioraent low ~ ιαά at ■ - ^:. ■:. · ■ - ^ ti ^ en: JlJj-n two i>^j; .uy :: rn ⁱ -ii: · ■ - ".- =" u '. "Γ'ρ

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to use auxiliary supports as counter bearings for the bridges, in the case of air-cooled machines, preferably from a local reinforced cooling air cladding can be formed.

In a further embodiment of the invention, it is proposed that the screw forces transmitted by the bridge via crowned Pressure surfaces and the intermediate layer corresponding to the surface pressure, which are planar or concave, on the cylinder head to transfer «The spherical pressure surfaces compensate for height differences of the bridge support, while the intermediate layers Compensate for displacements on all sides, so that no particular problems have to do with the accuracy of the position of the two cylinder units Requirements are made. TJm to achieve a favorable flow of forces in the screw forces, in particular for training a pressure cone, which distributes the forces as evenly as possible over the joint surface, is proposed, that the points of support of the bridge on the cylinder head are as far away as possible from the joining surface, e.g. on the upper cylinder head base, are arranged. To transfer the pressure forces from the bridge support to the joining surface, the Walls of the gas exchange ducts or supporting walls, ribs and stiffeners, the latter having a shape adapted to the air flow »

Another very simple embodiment results from the pre-cast free spaces for the expansion screws in the cylinder and cylinder head in the form of a continuous longitudinal groove, the so

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is dimensioned that the cooling air flow when passing through the '. (Drennfuge no significant throttling due to the screw shaft learns. Finally, it is proposed to limit the overall height of the machine to arrange the fastening elements in such a way that that they lie within the greatest overall height of the internal combustion engine formed by the cylinder head cover.

In the drawings, an embodiment of the invention is shown schematically. ™

Fig. 1 shows partially a longitudinal section through an air-cooled internal combustion engine, in which two cylinders are standing in ί view are shown «

. Fig. 2 shows the two cylinder units according to Fig. 1 in view

from above.
Fig. 3 shows a section through the two cylinder units in Fig. 1 according to the line III - III.

* Fig. 4 shows of the two cylinder units shown in Fig. 1 the sealing surface between cylinder head and cylinder and the position of the expansion screws and bridge support points.

In Fig. 1, two cylinders 1, 2 with cylinder heads 3, 4 are connected to a crankcase 8 by means of expansion screws 5 via bridges 6 and intermediate layers 7. The coil force is the one hand, on the cylinder heads 3 _t 4 and on the other hand transmitted to the constructed as auxiliary supports cooling air cladding 9 »10 on the outer sides of the cylinder units 1, 3-2; 4.

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In Fig. 2 the cylinder heads 3 * 4 are by means of the expansion screws 5 over the bridges 6 and the intermediate layers 7 with the one in the drawing crankcase not shown connected. On the outside ■ of the cylinder heads 3, 4, the screw force is applied to the transferred as cooling air cladding 9 »10 designed auxiliary supports.

In Abbo 3 the cylinder heads 3 »4 are at the level of the gas exchange ducts 11, 12-13, 14 cut transversely to the cylinder axis. The advantageous arrangement of the expansion screws 5 in the parting line two cylinder units shows the possible freedom of design for the gas exchange ducts, preferably the inlet ducts 11, and the favorable ribbing of the very hot inner parts 20 of the cylinder head. The direction of flow of the cooling air is through Marked with arrows. Here are the spaces 15 for Expansion screws 5 dimensioned sufficiently large as the transverse passage for the cooling air.

In Fig. 4 are the joint surfaces 16 of the cylinder heads and cylinders shown with their surface center lines 18. The means Bolt forces transmitted by bridges are applied to the cylinder head at the force application points 17 marked with a cross Transfer »The connecting lines 19 of the force application points 17 intersect the surface center line 10 of the joining surface. This advantageously results in a tilting of the cylinder head if the expansion screws are loosened or tightened on one side

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for the purpose of Llontagy or dismantling of the adjacent cylinder head prevented.

If the example shown shows force application points 17, which in the projection lie in pairs inside and outside of the vertical line 10 of the joining surface 16 are of course Arrangements in which all force application points 17 within the joining surface center line 18 are included in the invention. Also included are versions at where the joining surfaces do not have a circular shape, the force application points However, all or some of the projection onto the joining surface in a row machine does not have any tilting moment to the neighboring one Cylinder result.

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Claims (1)

5 Cologne-Deutz, Nov 10th 1969 D 69/65 - TP So / B Claims 1o J Cylinder head fastening for a reciprocating piston internal combustion engine in single and multi-row design with single cylinder heads, in which two adjacent cylinder heads with the cylinder and the crankcase are braced with one another by means of expansion screws, characterized in that two adjacent cylinder heads e 3 »4 by one or more expansion screws 5 are braced together with the crankcase 8 via a bridge. 2. Cylinder head attachment according to claim 1, characterized in that that two adjacent bridge support points 17 are arranged on the cylinder head 3, 4 so that their connecting line 19 in the vertical projection a chord to the surface center line 18 of the circular ring joining surface 16 between the cylinder head and forms cylinder. 3. Cylinder head attachment according to claim 1 or 2, characterized characterized in that auxiliary supports 9 »10 are used as counter bearings for the bridges 6 on the end cylinders. 4o cylinder head mounting according to one of claims 1 to 3 » characterized in that the tension forces of the bridge 6 correspond to spherical bearing surfaces and the surface pressure Intermediate layers 7 are transferred to the cylinder head 3, 4. 109826/0422 196180A 11/10/1969 D 69/65 5. Cylinder head attachment according to one of claims 1 to 4, characterized in that the support points 17 of the bridge on the cylinder head 3, 4 are as far as possible from the joining surface 16 remotely arranged approximately on the upper cylinder head base 21 are. 6. Cylinder head mounting according to one of claims 1 to 5 » characterized in that the pressure distribution of the forces introduced by the bridge 6 from the bridge support 17 to lying surface 16 through the 7 / other of the gas exchange channels 11, 12, 13 14 or by supporting walls, ribs or stiffeners, the latter having a shape adapted to the air flow. 7ο cylinder head mounting according to one of claims 1 to 6, characterized by da-3 for the expansion screw !! 5 free spaces 15 are pre-cast in cylinder 1, 2 and cylinder head 3, 4. ö. Cylinder head mounting according to one of claims 1 to 7 » thereby gykenuasichnüt that the expansion screws 5 with bridge 6 within the largest structural height of the internal combustion engine formed by the cylinder head cover 20 « I UST. · · .; ' r < i ■ ; λΰ Blank page